#! /usr/bin/env bash

# chkconfig: 2345 80 05
# description: Grafana web server & backend
# processname: grafana
# config: /etc/grafana/grafana.ini
# pidfile: /var/run/grafana.pid

### BEGIN INIT INFO
# Provides:          grafana
# Required-Start:    $all
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start grafana at boot time
### END INIT INFO

#  tested on
#  1. New lsb that define start-stop-daemon
#  3. Centos with initscripts package installed

PATH=/bin:/usr/bin:/sbin:/usr/sbin
NAME=grafana-server
DESC="Grafana Server"
DEFAULT=/etc/default/$NAME

GRAFANA_USER=grafana
GRAFANA_GROUP=grafana
GRAFANA_HOME=/usr/share/grafana
CONF_DIR=/etc/grafana
WORK_DIR=$GRAFANA_HOME
DATA_DIR=/var/lib/grafana
PLUGINS_DIR=/var/lib/grafana/plugins
LOG_DIR=/var/log/grafana
CONF_FILE=$CONF_DIR/grafana.ini
PROVISIONING_CFG_DIR=$CONF_DIR/provisioning
MAX_OPEN_FILES=10000
PID_FILE=/var/run/$NAME.pid
DAEMON=$GRAFANA_HOME/bin/grafana

umask 0027

if [ ! -x $DAEMON ]; then
  echo "Program not installed or not executable"
  exit 5
fi

. /lib/lsb/init-functions

if [ -r /etc/default/rcS ]; then
  . /etc/default/rcS
fi

# overwrite settings from default file
if [ -f "$DEFAULT" ]; then
  . "$DEFAULT"
fi

DAEMON_OPTS="server --pidfile=${PID_FILE} --config=${CONF_FILE} --packaging=deb cfg:default.paths.provisioning=$PROVISIONING_CFG_DIR cfg:default.paths.data=${DATA_DIR} cfg:default.paths.logs=${LOG_DIR} cfg:default.paths.plugins=${PLUGINS_DIR}"

function checkUser() {
  if [ `id -u` -ne 0 ]; then
    echo "You need root privileges to run this script"
    exit 4
  fi
}

case "$1" in
  start)
    checkUser
    log_daemon_msg "Starting $DESC"
    pid=`pidofproc -p $PID_FILE grafana`
    if [ -n "$pid" ] ; then
      log_begin_msg "Already running."
      log_end_msg 0
      exit 0
    fi

    # Prepare environment
    mkdir -p "$LOG_DIR" "$DATA_DIR" && chown "$GRAFANA_USER":"$GRAFANA_GROUP" "$LOG_DIR" "$DATA_DIR"
    touch "$PID_FILE" && chown "$GRAFANA_USER":"$GRAFANA_GROUP" "$PID_FILE"

    if [ -n "$MAX_OPEN_FILES" ]; then
      ulimit -n $MAX_OPEN_FILES
    fi

    # Start Daemon
    start-stop-daemon --start -b --chdir "$WORK_DIR" --user "$GRAFANA_USER" -c "$GRAFANA_USER" --pidfile "$PID_FILE" --exec $DAEMON -- $DAEMON_OPTS
    return=$?
    if [ $return -eq 0 ]
    then
      sleep 1
      # check if pid file has been written to
      if ! [[ -s $PID_FILE ]]; then
        log_end_msg 1
        exit 1
      fi
      i=0
      timeout=10
      # Wait for the process to be properly started before exiting
      until { cat "$PID_FILE" | xargs kill -0; } >/dev/null 2>&1
      do
        sleep 1
        i=$(($i + 1))
        if [ $i -gt $timeout ]; then
          log_end_msg 1
          exit 1
        fi
      done
    fi

    log_end_msg $return
    ;;
  stop)
    checkUser
    log_daemon_msg "Stopping $DESC"

    if [ -f "$PID_FILE" ]; then
      start-stop-daemon --stop --pidfile "$PID_FILE" \
        --user "$GRAFANA_USER" \
        --retry=TERM/20/KILL/5 >/dev/null
      if [ $? -eq 1 ]; then
        log_progress_msg "$DESC is not running but pid file exists, cleaning up"
      elif [ $? -eq 3 ]; then
        PID="`cat $PID_FILE`"
        log_failure_msg "Failed to stop $DESC (pid $PID)"
        exit 1
      fi
      rm -f "$PID_FILE"
    else
      log_progress_msg "(not running)"
    fi
    log_end_msg 0
    ;;
  status)
    status_of_proc -p $PID_FILE grafana grafana && exit 0 || exit $?
    ;;
  restart|force-reload)
    if [ -f "$PID_FILE" ]; then
      $0 stop
      sleep 1
    fi
    $0 start
    ;;
  *)
    log_success_msg "Usage: $0 {start|stop|restart|force-reload|status}"
    exit 3
    ;;
esac
